Stackable propellant module for gas generation

Abstract

This disclosure provides a stackable propellant module for use inside of a gas generation canister. The modules are designed to enable them to be individually fired rather than as a unitary mass, as done in conventional configurations. This enables the generation of a controlled pressure profile rather than an uncontrolled pressure profile determined by the environmental conditions downhole, such as temperature and pressure.

What is claimed is: 
     
       1. A method of controlling a pressure ramp rate associated with a gas generation event in a wellbore, comprising:
 placing a perforating tool in a wellbore, said perforating tool coupled to a wellbore gas generation canister system having one or more linearly stackable propellant modules located therein, wherein each of said one or more stackable propellant modules has an individually addressable igniter and a propellant contained within a module housing thereof; 
 perforating a casing of said wellbore with said perforating tool; and 
 subsequent to said perforating, igniting one or more of said linearly stackable propellant modules in an addressable manner using a controller wherein said controller sends an ignition signal to each of said addressable igniters in a time-delayed manner. 
 
     
     
       2. The method of  claim 1 , wherein each of said module housings is comprised of a propellant having a higher ignition point than an ignition point of said propellant contained within said module housings, each of said module housings having a thermal insulating layer located on an end of said module housing opposite an end on which said addressable igniters is located, and ejecting includes ejecting said thermal insulating layer into said spent module housing section. 
     
     
       3. The method of  claim 1 , further including ejecting at least a portion of said module housing of each of said one or more stackable propellant modules that is ignited. 
     
     
       4. The method of  claim 3 , wherein ejecting includes ejecting at least a portion of said module housing of each of said one or more stackable propellant modules that is ignited into a spent module housing section of said wellbore gas generation canister system. 
     
     
       5. The method of  claim 4 , wherein ejecting at least a portion of said module housing includes longitudinally sliding the at least a portion of said module housing. 
     
     
       6. The method of  claim 1 , wherein the gas generation canister housing has at least one or more vent holes located along a length thereof. 
     
     
       7. The method of  claim 6 , wherein said igniting one or more of said linearly stackable propellant modules in an addressable manner causes pressurized gas to exit the at least one or more vent holes and into the wellbore. 
     
     
       8. The method of  claim 1 , wherein each of said module housings is comprised of a propellant having a lower porosity and lower surface area per volume than said propellant located within said module housing. 
     
     
       9. The method of  claim 1 , wherein each of said igniters is located within each of said propellants and on a central axis of each of said housings. 
     
     
       10. The method of  claim 1 , wherein said gas generation canister further includes an electronic control system coupled to each of said igniters. 
     
     
       11. The method of  claim 1 , wherein said gas generation canister further includes a pressure sensor. 
     
     
       12. The method of  claim 1 , wherein said controller is configured to receive pressure readings from a pressure sensor and time a firing of the one or more linearly stackable propellant modules in real time. 
     
     
       13. The method of  claim 1 , wherein said controller fires the one or more linearly stackable propellant modules with time delays so that a desired wellbore pressure ramp rate can be achieved. 
     
     
       14. The method of  claim 1 , wherein said controller fires the one or more linearly stackable propellant modules with time delays so that a final desired wellbore pressure is achieved. 
     
     
       15. A method of controlling a pressure ramp rate associated with a gas generation event in a wellbore, comprising:
 placing a perforating tool in a wellbore, said perforating tool coupled to a wellbore gas generation canister system having one or more linearly stackable propellant modules located therein, wherein each of said one or more stackable propellant modules has an igniter and a propellant contained within a module housing thereof; 
 perforating a casing of said wellbore with said perforating tool; and 
 subsequent to said perforating, igniting one or more of said linearly stackable propellant modules, the igniting causing a module housing of the ignited linear stackable propellant modules to linearly slide within the wellbore gas generation canister. 
 
     
     
       16. The method of  claim 15 , wherein the igniting causes the module housing of the ignited linear stackable propellant modules to linearly slide into a spent module housing section of said wellbore gas generation canister system. 
     
     
       17. The method of  claim 16 , wherein the ignitor is an individually addressable ignitor and further wherein each of said module housings is comprised of a propellant having a higher ignition point than an ignition point of said propellant contained within said module housings, each of said module housings having a thermal insulating layer located on an end of said module housing opposite an end on which said addressable ignitor is located, and linearly sliding includes linearly sliding said thermal insulating layer. 
     
     
       18. The method of  claim 15 , wherein the gas generation canister housing has at least one or more vent holes located along a length thereof. 
     
     
       19. The method of  claim 18 , wherein said igniting one or more of said linearly stackable propellant modules causes pressurized gas to exit the at least one or more vent holes and into the wellbore. 
     
     
       20. The method of  claim 15 , wherein each of said module housings is comprised of a propellant having a lower porosity and lower surface area per volume than said propellant located within said module housing. 
     
     
       21. The method of  claim 15 , wherein each of said igniters is located within each of said propellants and on a central axis of each of said housings. 
     
     
       22. The method of  claim 15 , wherein said gas generation canister further includes an electronic control system coupled to each of said igniters. 
     
     
       23. The method of  claim 15 , wherein said gas generation canister further includes a pressure sensor.